Dual-color projector

ABSTRACT

A dual-color projector is disclosed that includes a blue laser device configured to emit a blue laser light, a red laser device configured to emit a red laser light, and a fluorescent wheel whose surface is coated with green fluorescent powder which is excitable by the blue laser light to emit a green fluorescent light. The dual-color projector may also include a first diffusion element and a second diffusion element.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation patent application of U.S. patentapplication Ser. No. 15/895,803, filed on Feb. 13, 2018, which in turnis a continuation of International Patent Application No.PCT/CN2015/088940, filed on Sep. 6, 2015 and claims priority to ChinesePatent Application No. 201510298318.7, filed Jun. 3, 2015, the entiretyof all of which are incorporated by reference herein.

TECHNICAL FIELD

The present disclosure relates to the field of projection display, inparticular to a dual-color laser light source and a projection displaydevice.

BACKGROUND

Laser light is a light source emitting monochromatic coherent beams,with high luminance and strong directionality. Owing to the numerousadvantages, the laser light has been gradually applied as a light sourcein the technical field of projection display in recent years. However,because of the high coherence of laser, the speckle effect isinevitable, such phenomenon is especially obvious in the solutionswithin which a pure laser light is used as the light source, and it alsoexists in the solutions within which a laser light and a fluorescentlight are used, as well as in the solutions within which the mixed lightsource of a laser light and a LED is used. The speckle refers to thespatial interference of the light after scattering when a coherent lightsource irradiates on a rough object, and the spatial interference of thelight is owing to the same wave length and the constant phase of thelight. There will be some constructive spatial interference and somedestructive spatial interference, the final result is that alternatedlight and shade granular spots will appear on the screen, namely, someunfocused spots will flash, it is easy to feel dizzy after watching forlong time. And it will undoubtedly result in the quality reduction ofprojected images to lower the user's experience of watching.

The use of a bicolor laser light source improves the overall luminanceof the laser light source to satisfy the need of the luminance in thefield of laser projection. However, the speckle problems caused by thelaser light itself also will be aggravated, which becomes an obstacle tothe popularization and application of the bicolor laser light.

How to reduce the speckle effect of a laser light caused by its inherentqualities at the same time of applying a bicolor laser light source hasbecome a technical problem to be solved.

SUMMARY

According to a first embodiment, the disclosure provides a dual-colorprojector, comprising:

a blue laser emitter configured to emit a blue light and a red laseremitter configured to emit a red light;

a fluorescent wheel whose surface is coated with green fluorescentpowder which can be excited by the blue light to emit a greenfluorescent; and,

a first diffuser, which is fixedly disposed in at least one of the lightpath of the blue light or the light path of the red light;

a second diffuser, which is controlled to rotate and disposed at anupstream side of a lightpipe in a light path between the second diffuserand the lightpipe;

wherein the second diffuser is configured to output the blue light andthe red light in time sequence to the lightpipe.

According to another embodiment, the disclosure provides a dual-colorprojector, comprising:

a blue laser emitter configured to emit a blue light and a red laseremitter configured to emit a red light;

a fluorescent wheel comprising a first zone and a second zone, the firstzone is coated with green fluorescent powder, the second zone istransmissive for the blue light;

a first diffuser, which is fixedly disposed in the light path of theblue light between the blue laser emitter and a light-combining element;

the light-combining element configured to receive the blue light outputby the first diffuser and the red light, and output the blue light tothe fluorencent wheel, output the red light to a second diffuser in afirst direction, wherein a first part of the blue light is configured toexcite the green fluorescent powder to emit a green fluorescent, asecond part of the blue light is configured to pass through the secondzone;

a first reflector system configured to change direction of the secondpart of the blue light passed through the second zone and render thesecond part of the blue light passed through the second zone to incidenton the light-combining element,

the light-combining element also configured to receive the second partof the blue light output by the first reflector system and the greenfluorescent emitted from the fluorescent wheel, and output the secondpart of the blue light and the green fluorescent to the second diffuserin the first direction;

the second diffuser, which is controlled to rotate and disposed at anupstream side of a lightpipe in a light path between the second diffuserand the lightpipe, wherein the second diffuser comprises a green filterconfigured to filter the green fluorescent output by the light-combiningelement, a blue light diffusion zone configured to diffuse the secondpart of the blue light output by the light-combining element and a reddiffusion zone configured to diffuse the red light output by thelight-combining element;

the lightpipe configured to receive the green fluorescent output by thesecond diffuser, the second part of the blue light output by the seconddiffuser and the red light output by the second diffuser.

In yet another embodiment, the disclosure provides a dual-colorprojector, comprising:

a blue laser emitter configured to emit a blue light and a red laseremitter configured to emit a red light;

a fluorescent wheel comprising a first zone and a second zone, the firstzone is coated with green fluorescent powder, the second zone istransmissive for the blue light;

a first diffuser, which is fixedly disposed in the light path of the redlight between the red laser emitter and a light-combining element;

the light-combining element configured to receive the red light outputby the first diffuser and the blue light, and output the blue light tothe fluorencent wheel, output the red light to a second diffuser in afirst direction, wherein a first part of the blue light is configured toexcite the green fluorescent powder to emit a green fluorescent, asecond part of the blue light is configured to pass through the secondzone;

a first reflector system configured to change direction of the secondpart of the blue light passed through the second zone and render thesecond part of the blue light passed through the second zone to incidenton the light light-combining element,

the light-combining element also configured to receive the second partof the blue light output by the first reflector system and the greenfluorescent emitted from the fluorescent wheel, and output the secondpart of the blue light and the green fluorescent to the second diffuserin the first direction;

the second diffuser, which is controlled to rotate and disposed at anupstream side of a lightpipe in a light path between the second diffuserand the lightpipe, wherein the second diffuser comprises a green filterconfigured to filter the green fluorescent output by the light-combiningelement, a blue light diffusion zone configured to diffuse the secondpart of the blue light output by the light-combining element and a reddiffusion zone configured to diffuse the red light output by thelight-combining element;

the lightpipe configured to receive the green fluorescent output by thesecond diffuser, the second part of the blue light output by the seconddiffuser and the red light output by the second diffuser.

In yet another embodiment, the disclosure provides a dual-colorprojector, comprising:

a blue laser emitter configured to emit a blue light and a red laseremitter configured to emit a red light;

a fluorescent wheel comprising a first zone and a second zone, the firstzone is coated with green fluorescent powder, the second zone istransmissive for the blue light;

a first fixed diffuser, which is fixedly disposed in the light path ofthe blue light between the blue laser emitter and a light-combiningelement;

a second fixed diffuser, which is fixedly disposed in the light path ofthe red light between the red laser emitter and the light-combiningelement;

the light-combining element configured to receive the blue light outputby the first fixed diffuser and the red light output by the second fixeddiffuser, and output the blue light to the fluorencent wheel, output thered light to a rotating diffuser in a first direction, wherein a firstpart of the blue light is configured to excite the green fluorescentpowder to emit a green fluorescent, a second part of the blue light isconfigured to pass through the second zone;

a first reflector system configured to change direction of the secondpart of the blue light passed through the second zone and render thesecond part of the blue light passed through the second zone to incidenton the light light-combining element,

the light-combining element also configured to receive the second partof the blue light output by the first reflector system and the greenfluorescent emitted from the fluorescent wheel, and output the secondpart of the blue light and the green fluorescent to the rotatingdiffuser in the first direction;

the rotating diffuser, which is controlled to rotate and disposed at anupstream side of a lightpipe in a light path between the second fixeddiffuser and the lightpipe, wherein the rotating diffuser comprises agreen filter configured to filter the green fluorescent output by thelight-combining element, a blue light diffusion zone configured todiffuse the second part of the blue light output by the light-combiningelement and a red diffusion zone configured to diffuse the red lightoutput by the light-combining element;

the lightpipe configured to receive the green fluorescent output by therotating diffuser, the second part of the blue light output by therotating diffuser and the red light output by the rotating diffuser.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic diagram of a dual-color laser light source insome embodiments of the disclosure;

FIG. 2 shows a schematic diagram of another dual-color laser lightsource in some embodiments of the disclosure;

FIG. 3 shows a schematic diagram of the plan view of a fluorescencewheel in some embodiments of the disclosure;

FIG. 4 shows a schematic diagram of a second diffusion plate in someembodiments of the disclosure;

FIG. 5 shows a schematic diagram of the zones of another seconddiffusion plate in some embodiments of the disclosure;

FIG. 6 shows a schematic diagram of the Gaussian distribution of thelaser beam energy in some embodiments of the disclosure.

FIG. 7 shows a schematic diagram of yet another dual-color laser lightsource in some embodiments of the disclosure;

FIG. 8 shows a schematic diagram of yet another dual-color laser lightsource in some embodiments of the disclosure;

FIG. 9 shows a structural diagram of a projection display device in someembodiments of the disclosure;

FIG. 10 is the structural diagram of another projection display devicein some embodiments of the disclosure.

DETAILED DESCRIPTION

In order to make the objects, technical solutions and advantages of thedisclosure clearer, the disclosure will be further described in detailsbelow by combining with the drawings. The embodiments described may onlyrepresent partial embodiments of the disclosure and not an entirety ofan embodiments. Based on the embodiments in the disclosure, all theother embodiments obtained by a person of skill in the art withoutcreative labor are within the protective scope of the disclosure.

The embodiments of the disclosure provides a dual-color laser lightsource. As shown in FIG. 1, the dual-color laser light source comprisesa blue laser emitter array 11 configured to emit a blue laser light anda red laser emitter array 12 configured to emit a red laser light, aswell as a fluorescent wheel 4, on the surface thereof green fluorescentpowder is coated, and the green fluorescent powder can be excited by theblue laser light to emit a green fluorescent light. The blue laser lightand the red laser light are shaped by a beam shaping device 2 beforeentering the fluorescent wheel 4 and a light merging component 5. Thebeam shaping device 2 comprises the first diffusion element 31 of thespeckle dissipation system 3, wherein the first diffusion element 31 isfixedly disposed and in the beam shaping optical path(s) of the bluelaser light and the red laser light, and is configured to diffuse theblue laser light and the red laser light. The blue laser light isreflected to the fluorescent wheel 4 by the light merging component 5,and then reach the light merging component 5 again through beingtransmitted by the fluorescent wheel 4 and a optical path of a relayloop, and at last is reflected to output by the light merging component.The red laser light is reflected by the light merging component 5 andthe green fluorescent light is transmitted by the light mergingcomponent 5. The second diffusion element 32 is controlled to rotated,that is, which is a moving diffusion element. And the second diffusionelement 32 is disposed before the blue laser light, the red laser lightand the green fluorescent light incidenting into a light bar 6, and isconfigured to transmit at least the blue laser light and the red laserlight in time sequence. The second diffusion element 32 can output theblue laser light and the red laser light in time sequence based ontransmitting at least the blue laser light and the red laser light intime sequence by its rotation, therefore it can be configured to outputthe three primary colors for the light source system. The seconddiffusion element 32 and the first diffusion element 31 form the speckledissipation system of the laser light source in the embodiments of thedisclosure.

The light bar 6 collects the lights of three primary colors to transmitthem into a light machine part, so as that the laser light sourceproviding illumination for the light machine part is realized.

In the embodiments of the disclosure, since the blue laser light and thered laser light pass the first diffusion element and the seconddiffusion element of the speckle dissipation system 3 in order, twodiffusion elements within which one is fixedly disposed and the other ismoving can be used at the same time to dissipate speckles for the bluelaser light and the red laser light. The technical problem of lowdisplay quality of the projected images brought by the speckle effect issolved when a dual-color laser light source is used; in addition theblue laser light and the red laser light can be output in time sequenceand used to provide the light source system with three primary colors.

The embodiments of the disclosure provides another laser light source.As shown in FIG. 2, the blue laser emitter array 11 being configured tooutput the blue laser light is arranged vertical to the red laseremitter array 12 being configured to output the red laser light, and thebeams emitted by the vertically arranged arrays are also vertical toeach other. This kind of arrangement helps to reduce the volume occupiedby the laser light devices, at the same time helps to the commonly useof the beam shaping device.

The laser light spot emitted by the laser emitter may have unevenluminance and too big beam area, in turn result in many problems such aslow light transmittance of the optical components and low efficiency offluorescent excitation, as well as low collection efficiency resulted bythe radial angle of the laser beam being greater than the collectionangle of the light bar to influence the luminance of the light sourcefor projection. Hence the beam shaping of reflection, refraction, etc.for the laser light is required to reduce the beam area and homogenizethe beam energy. The laser beam can be used for illumination only afterbeing beam shaped, as well as for the subsequent fluorescent excitationby the fluorescent wheel.

The first diffusion element is fixedly disposed at the rear end of thebeam shaping optical path(s) of the blue laser light and the red laserlight, and is configured to diffuse the blue laser light and the redlaser light. As shown in FIG. 2, the beam shaping device 2 comprises areflector element 21, a convex lens 22 and a concave lens 23, and thebeam shaping device 2 also comprises a first diffusion element 31 behindthe concave lens. The first diffusion element is fixedly disposed. Theconvex lens 22 and the concave lens 23 form a telescope system. The beamshaping device performs the shaping of reflection, beam bunching andhomogenization in order for the blue laser light and the red laserlight.

The reflector element 21 is arranged in front of the blue and the redlaser emitter arrays and is arranged at an included angle of 45° withthe two laser light arrays. The reflector element 21 can be composed bya set of reflectors at intervals, the lens part of the reflectors canreflect one light source, the interval between the reflectors can allowto transmit another light source. Accordingly, the reflection for onelight source of the blue and the red laser light sources and thetransmission for the other light source only by using one reflectorelement, so that it not only can reduce the beam separation of the beamsoutput by the two laser light arrays and output the synthetic beam inthe same direction, it can also reach the object of compact structure.

Before reaching the reflector element 21, the blue laser light and thered laser light also passes a collimating lens (not shown in the figure)for collimation to reduce the angle of diffusion for the laser lightrespectively, so that more quantity of light can reach or transmitthrough the reflector element to improve the shaping efficiency of thelaser light.

After beam combination by the reflector element 21, the blue laser lightand the red laser light pass through the telescope system composed ofthe convex lens 22 and the concave lens 23 in order, the telescopesystem here is configured to bunch the laser beam, reduce the size ofthe light spot or the beam area, and improve the transmittance of thebeam in the optical devices at the rear end.

After passing the telescope system, the blue laser light and the redlaser light pass through and shot out from the first diffusion element31 for a first diffusion, wherein the blue laser light incidents intothe fluorescent wheel 4 after transmitting the first diffusion element31, and the red laser light incidents into a light merging component 5after transmitting the first diffusion element 31. No matter for the redlaser light or the blue laser light, the first diffusion element willdiffuse the laser beams. On the one hand, it can increase the spacialphases of the laser beams and destroy to a certain extent the constantphase which is the condition for producing interference, and the purposeof certain speckle dissipation can be achieved; on the other hand, thediffusion of the laser beams can also homogenize the beam energy, whichis very important for the blue laser light, since the blue laser lightserves as the excited light of the fluorescence wheel. And if the bluelaser beam is not homogenized, it may cause that the surface of thefluorescence wheel is burned out and damaged by the laser beam with morecentralized light intensity when the laser light directly incident onthe surface of the fluorescence wheel under uneven intensitydistribution and centralized energy, the burning out and the damagingwill result in that the fluorescence wheel is unable to normally excitethe fluorescent light.

To dispose the first diffusion element 31 at the rear end of the beamshaping optical path(s), it is considered that the laser beam has asmall light spot area through bunching, thus it is favorable fortransmitting the laser beam into the optical system below through theoptical lens, and at that time the diffusion efficiency of the laserbeam can be improved. At the same time, in order to achieve thecondition for exciting the the fluorescence wheel when the laser lightincidents into it, the last homogenization of the light spot must beperformed for the uniform distribution of energy.

Specifically, the first diffusion element 31 may be a diffusion plate,on the surface thereof diffusers may be coated in uniform distribution.Frosted glass or two-dimensional components can be chosen, which canproduce diffuse reflection for light and destroy the directionality ofthe laser light. Microstructures may also be manufactured on the surfaceof the diffusion plate, which may play the same effect of diffusereflection.

An image is composed of three primary colors of red, green and blue. Inthe embodiments of the disclosure, the laser lights have already couldprovide two primary colors of blue and red, and a wavelength converteris also required to produce one color of three primary colors, that is,green. A fluorescent wheel is a normally used wavelength converter,which has a shaft and can be driven by the motor to rotate. As shown inFIG. 3, the fluorescence wheel 4 comprises a reflection part 41 and atransmission part 42, and the transmission part 42 is used fortransmitting the excitation light. According to the principle that alight of a short wavelength can excite a light of a long wavelength, theblue laser light is selected as the excitation light. The surface of thereflection part 41 is coated with green powder. The reflection part 41and the transmission part 42 are alternately in the position into whichthe excitation light source incidents when the fluorescent wheel 4rotates. Accordingly, when the laser light incidents into the surface ofthe fluorescence wheel, it can not only transmit a portion of the laserlight, but can also be excited by another portion of the laser light toemit the fluorescent light. When the fluorescence wheel 4 rotates to theposition of the reflection part 41, the blue laser light irradiates thegreen fluorescent powder to emit the green fluorescent light which isreflected by the surface of the fluorescence wheel 4 to reach the lightmerging component 5. When the fluorescence wheel rotates to the positionof the transmission part 42, the transmission part can be transparentglass, the blue laser light will transmit the transmission part 42 andthen return to the light merging component 5 from the back of thefluorescence wheel 4 through the loop of the blue laser light, and theloop of the blue laser light is usually composed of relay lenses andreflectors.

In some embodiments of the disclosure, a collimating lens set can bearranged on the front/back of the fluorescence wheel 4 and used forreducing the angles of diffusion for the transmitted laser light orreflected fluorescent light and enhancing the degree of beamconvergence.

The red laser light after beam shaping transmits the first diffusionplate and then directly incidents into the light merging component 5.And in the embodiments of the disclosure, the light merging component 5can choose an X light merging lens.

The X light merging lens is composed of two lenses crossly arranged inan “X” shape, which has a color selection effect of reflecting A lightand transmitting B light or reflecting B light and transmitting A lightrespectively through applying coatings on its surface. For example, alens for reflecting red laser light and transmitting green fluorescentlight, or a lens for reflecting green fluorescent light and transmittingred laser light and blue laser light, and the high reflectance and hightransmittance of light can be realized by applying reasonable coatingson the light merging lens and keeping the light away from the area withlow transmittance in the center of the lens as much as possible in thedesign of the optical path.

In the embodiments of the disclosure, the X light merging lens 5 iscomposed of a lens for reflecting blue and transmitting red and greenand a lens for reflecting red and transmitting blue and green, wherein,the lens for reflecting red and transmitting blue and green can reflectthe red laser light and transmit the blue laser light, the transmittedblue laser light is then reflected by another lens for reflecting blueand transmitting red and green to the fluorescence wheel, finally itreturns to the X light merging lens 5 after being conversed in a seriesof optical path conversions and then is reflected by the lens forreflecting blue and transmitting red and green in the X light merginglens 5. Whereas, the excited green fluorescent light is reflected by thefluorescence wheel to the X light merging lens 5 and is transmitted byboth the lens for reflecting red and transmitting blue and green and thelens for reflecting blue and transmitting red and green of the X lightmerging lens 5. And the red laser light is firstly reflected by the lensfor reflecting red and transmitting blue and green, then reaches andtransmits the lens for reflecting blue and transmitting red and green.The transmission path of the three colors of light in the X lightmerging lens is as shown by the optical path in FIG. 2. Finally, the redlaser light, the blue laser light and the green fluorescent light allpass the X light merging lens 5 to form a white light and transmit inthe same direction.

In order for more effective speckle dissipation for the laser light, thelaser light and the fluorescent light also passes the second diffusionelement 32 of the speckle dissipation system. The second diffusionelement 32 can be controlled to rotate by a motor. Specifically, thesecond diffusion element 32 may be a structure of a color wheel. Asshown in FIG. 4, the color wheel comprises a diffusion zone 321 beingconfigured to transmit the blue laser light and the red laser light anda non-diffusion zone 322 being configured to transmit the greenfluorescent. The diffusion zone and the non-diffusion zone are splicedto form the wheel face of the color wheel.

The diffusion zone 321 may be made of diffusion material and on thesurface thereof diffusers may be coated or microstructures may bemanufactured. In order to diffuse the blue laser light and the red laserlight respectively, the diffusion zone 321 is divided into a blue laserlight diffusion zone 321B and a red laser light diffusion zone 321R, asshown in FIG. 5, which are configured to transmit the blue laser lightand the red laser light in time sequence when the second diffusionelement rotates.

The non-diffusion zone 322 may be a green color filter plate or may betransparent material, such as transparent glass, and is configured totransmit and guide the green fluorescent light into the light bar 6 forhomogenization. The second diffusion element plays a role of outputtingthe green fluorescence light as a color filter when the non-diffusionzone 322 is a green color filter plate, hence the color purity of greenfluorescence light will be improved.

The fan-shaped areas or the central angles occupied by the blue laserlight diffusion zone 321B and the red laser light diffusion zone 321R onthe color wheel are usually different when considering the proportion ofred and blue needed in the white balance of the light source system,therefore the coated areas of the diffusers on these two diffusion zonesare also usually different. For example, in the embodiments of thedisclosure, three central angles of zones corresponding to red, greenand blue account for 15%, 25% and 60%, respectively. Specifically, thecentral angle of the blue laser light diffusion zone 321B is 54°, thecentral angle of the red laser light diffusion zone 321R is 90°, and thecentral angle of the non-diffusion zone is 216°. The above center angledistribution of the color wheel for the red laser light diffusion zone,the blue laser light diffusion zone and the non-diffusion zone on thesecond diffusion element is just an example, the color proportions of R,G and B are related with the white balance required by the light sourcesystem, which will be not limited to the above numerical range. Thewhite balance is an indicator for describing the accuracy of the whitecolor obtained by merging the three primary colors of red, green andblue in a display device. The white balance will be affected by thefactors of color temperature, ambient light, etc., and different whitebalances will display different image tones. Moreover, in the aboveembodiment, if the system has serious speckling phenomenon, it isnecessary to reduce the angle of the non-diffusion zone and increase theangle of the diffusion zone, and the diffusion zone of a big angle isused to weaken the speckling phenomenon.

Although the blue laser light and the red laser light have closecoherence, owing to the different sensitivity of human eyes to thespeckles formed by the red laser light and the blue laser light, theactual situation is that human eyes have higher sensitivity to thespeckles formed by the red laser light, and thus more attentions shallbe paid to the speckle dissipating of the red laser light. The red laserlight diffusion zone 321R may comprise multiple diffusion subzones; themultiple diffusion subzones have different angles of diffusion for thered laser light. Among the multiple diffusion subzones, the angles ofdiffusion for the red laser light of the diffusion subzones in themiddle can be greater than the angles of diffusion for the red laserlight of the diffusion subzones on both sides, and the areas of thediffusion subzones in the middle are also bigger than the areas of thediffusion subzones on both sides; the reason for such arrangement isconsidering that energy distribution of the laser light is of theGaussian type, and as shown in FIG. 6, the energy of the laser beam ismore centralized in the middle. As a result, the diffusion zones closerto the middle requires for greater angle of diffusion and bigger areaproportion to effectively diverge the laser beam with more centralizedenergy.

As shown in FIG. 5, the red laser light diffusion zone is divided into 3red laser light diffusion subzones, Ra, Rb and Rc, wherein, thefan-shaped central angle is 45° for Rb, 20° for Ra and 25° for Rc. Theangle of diffusion for the diffuse reflector at Rb can be set as5°˜5.5°, the angle of diffusion for the diffuse reflector at Ra can beset as 2°˜2.5°, and the angle of diffusion for the diffuse reflector atRc can be set as 2.5°˜3°, the gradual arrangement owing to such settingsof the diffusion subzones of the red laser light diffusion zone canrealize the effective decoherence for the Gaussian beams of the laserlight.

In this embodiment, the work process of the speckle dissipation of thelaser light is that: according to the lighting sequence of the laseremitters, when the blue laser emitter is lighted, the blue laser lightafter beam shaping transmits the first diffusion element 31 to realizethe preliminary decoherence and homogenization, and is reflected by theX light merging lens 5 to the fluorescence wheel 4, and is transmittedby the transmission part 42 of the fluorescence wheel when thefluorescence wheel 4 rotates to the position of the transmission part42, and then is converted by the optical path of the relay loop to reachthe X light merging lens 5 for reflection and output again. At thatmoment, the second diffusion element 32 rotates to the position of theblue laser light diffusion zone 321B, so that the blue laser light isdiffused by the moving diffusion element and then output to form theblue laser light. When the fluorescence wheel 4 rotates to thereflection part 41, the blue laser light irradiates the greenfluorescent powder in the circumference on the surface of the reflectionpart 41, the emitted green fluorescent light is reflected by thefluorescence wheel and transmitted and output through the X lightmerging lens 5. At that moment, the second diffusion element 32 rotatesto the position of the non-diffusion zone 322, such as a green colorfilter, so that the color filter wheel 7 rotates to the position of thegreen light filter plate, so that the green fluorescent light transmitsthe green color filter of the moving second diffusion element 32 to formthe green light by colors being filtered.

In the similar way, when the red laser emitter is lighted, the red laserlight through the beam shaping device transmits the first diffusionelement 31 to realize the preliminary decoherence, it reaches the Xlight merging lens and is reflected by it. At that moment, the seconddiffusion element 32 rotates to the position of the red laser lightdiffusion zone 321R, the red laser light will pass through Ra, Rb and Rcin order along with the rotation of the red laser light diffusion zone321R, the red laser light suffers another diffusion, so that the redlaser light is diffused by the red laser light diffusion zone 321R andthen output to form the red laser light.

In the technical solution of embodiments within which a dual-color laserlight source is provided, the blue laser light emitted by the blue laseremitter and the red laser light emitted by the red laser emitter firstlypass the fixedly disposed first diffusion element 31, which is diffusionmaterial and can increase the spacial phases of the blue laser beam orthe red laser beam and destroy to a certain extent the constant phasewhich is the condition for producing interference. After merging withthe fluorescent light, the blue laser light and the red laser light passthe moving second diffusion element 32, which is diffusion material,since the moving diffusion element itself can produce some randomspatial phases for the laser beam compared with the fixedly arrangeddiffusion element, and accordingly it can effectively destroy thecoherence of the laser light; whereas, in the embodiment of thedisclosure, the moving diffusion element can further increase morerandom phases on the basis of the spatial phases increased by the fixeddiffusion element by matching the fixed diffusion element with themoving diffusion element, so that the degree of decoherence for the bluelaser beam and the red laser beam will be higher, more independentspeckle patterns can be formed on the projected image, however, the morethe independent speckle patterns are, the weaker the phenomenon of lightand shade spots will be by using the integral action of human eyes, andaccordingly the speckle effect of the laser light can be effectivelyweakened to improve the display quality of projected images.

Besides, the embodiment of the disclosure also divides the red laserlight diffusion zone in the second diffusion element into multiplediffusion subzones according to the characteristic that human eyes aremore sensitive to the speckles of the red laser light, and the diffusionsubzones in the middle have both bigger areas and greater angles ofdiffusion for the red laser light than the diffusion subzones on bothsides, so that the speckle dissipation effect on the red laser light canbe enhanced according to the characteristics of Gaussian distribution ofthe laser beams.

Besides, in the embodiment of the disclosure, the second diffusionelement is a structure of a color wheel, and comprises a diffusion zoneand a non-diffusion zone. The diffusion zone and the non-diffusion zoneare spliced to form the wheel face of the color wheel. The diffusionzone and the non-diffusion zone are spliced to form the wheel face andoutput the blue laser light, the red laser light and the green light intime sequence when the color wheel rotates, that is, output the threeprimary colors in time sequence, therefore the second diffusion elementhas both the functions of dissipating speckles for the laser lightsource and outputting three primary colors for the light source system,then the usage of a color filter wheel can be omitted and theutilization of the optical components in the light source system can beimproved, and the light source system architecture is advantageously tobe simplified.

Moreover, in the embodiment of the disclosure, a speckle dissipationsystem being composed of the first diffusion element and the seconddiffusion element is shared for the speckle dissipation of the bluelaser light and the red laser light, rather than to design the opticalpath of speckle dissipation for each of the laser light, the complexityof the optical path of the light source is reduced, and the efficiencyof the speckle dissipation is improved.

Similar to the laser light source illustrated by FIG. 2, the laseremitter in some embodiments of the disclosure as shown in FIG. 7comprises a blue laser emitter array 11 and a red laser emitter array12. The blue laser light and the red laser light share a speckledissipation system composed of a fixedly disposed first diffusionelement 31 and a moving second diffusion element 32, so that the speckleeffect of the blue and red laser lights can be weakened at the same timeto achieve the speckle dissipation effect on the laser light source. Themain differences between FIG. 7 and FIG. 2 are that the beam shapingdevices used are different. Therefore, the same structures and functionsas those in FIG. 2 will not be repeated, and the differences in FIG. 7will be mainly described.

As shown in FIG. 7, the beam shaping device 2 comprises a reflectorelement 21, a convex lens 22, a concave lens 23, and a fixedly disposedfirst diffusion element 31 behind the concave lens. The convex lens 22and the concave lens 23 form a telescope system. The beam shaping deviceperforms the shaping of reflection, beam bunching and homogenization forthe blue laser light and the red laser light in order.

The reflector element 21 is arranged in front of the blue and the redlaser emitter arrays and is arranged at an included angle of 45° withthe two laser light arrays. The reflector element 21 can be composed bya set of reflectors at intervals, the lens part of the reflectors canreflect one light source, the interval between the reflectors can allowto transmit another light source. In some embodiments of thisdisclosure, the reflector element 21 can be a dichroism sheet.Accordingly, the reflection for one light of the blue and the red laserlights and the transmission for another light only by using onereflector element, so that it not only can reduce the beam separation ofthe beams output by the two laser light arrays and output the syntheticbeam in the same direction, it can also reach the object of compactstructure.

In the state shown in FIG. 7, the reflector element 21 may transmit thered laser light emitted by the red laser array below it and reflect theblue laser light emitted by the blue laser array on its right.

The blue laser light and the red laser light may be merged by thereflector element 21 pass the telescope system composed of the convexlens 22 and the concave lens 23, and the first diffusion element 31 inorder. This optical path and the optical path thereafter are the same asthose in FIG. 2, and the details will not described herein again.

As shown in FIG. 8, another laser light source is provided in someembodiments of the disclosure. The main differences between FIG. 8 andFIG. 2 are also that the beam shaping devices used are different.Therefore, the same structures and functions as those in FIG. 2 will notbe repeated, and the differences in FIG. 8 will be mainly described.

As shown in FIG. 8, the beam shaping device 2 comprises a reflectorelement 21, two convex lenses 22, a concave lenses 23, and a fixedlydisposed first diffusion element 31 behind each of the concave lens.Each of the convex lens 22 and the corresponding concave lens 23 form atelescope system. The beam shaping device in FIG. 8 performs the shapingof beam bunching, homogenization and reflection in order for the bluelaser light and the red laser light, which is different from the theshaping of reflection, beam bunching and homogenization performed inFIGS. 2 and 7 for the blue laser light and the red laser light in order.

In the laser light source illustrated by FIG. 8, a telescope system anda fixedly disposed first diffusion element 31 behind the telescopesystem are arrange for each of the blue laser array 11 and the red laseremitter array 12. The blue laser light and the red laser light incidentinto the reflector element 21 after the shaping of beam bunching andhomogenization performed by its corresponding telescope system and firstdiffusion element 31, respectively.

The reflector element 21 is arranged in front of its first diffusionelement 31 and is arranged at an included angle of 45° with the twofirst diffusion elements 31. The reflector element 21 can be composed bya set of reflectors at intervals, the lens part of the reflectors canreflect one light source, the interval between the reflectors can allowto transmit another light source. Accordingly, the reflection for onelight of the blue and the red laser lights and the transmission foranother light only by using one reflector element, so that it not onlycan reduce the beam separation of the beams output by the two laserlight arrays and output the synthetic beam in the same direction, it canalso reach the object of compact structure.

In the state shown in FIG. 8, the reflector element 21 may transmit thered laser light emitted by the red laser array below it and reflect theblue laser light emitted by the blue laser array on its right.

The blue laser light and the red laser light may be merged by thereflector element 21 pass the fluorescence wheel 4 and the light mergingcomponent 5 in order. This optical path and the optical path thereafterare the same as those in FIG. 2, and the details will not describedherein again.

Some embodiments of the disclosure provides a projection display device,as shown by the schematic diagram in FIG. 9, the projection displaydevice comprises a laser light source 91, a light machine 92, a lens 93and a projection screen 94.

The laser light source adopts the laser light source in the aboveembodiments, three primary lights sequentially output three primarycolors; the primary colors enter the light machine 92 through the lightbar (not shown in the figure), in addition to the light bar, the lightmachine 92 part also comprises an optical path converter and a DMD chip(both not shown in the figure). The DMD chip can be considered as beingcomposed of numerous tiny reflectors, these tiny reflectors can turnover driven by current within a certain range of angle to regulate thequantity of light entering the lens, so that different colors candisplay on the images. After being modulated by the DMD, the threeprimary colors of light reach the lens 93 by refraction and convergencefor multiple times.

The projection device in the embodiment is a projection device withultra-short focus, it is applicable for household or portable use. Thusthe lens 93 is a projection lens with ultra-short focus, and theprojection lens with ultra-short focus has the characteristic that itcan still project high-quality images at a low projection ratio. Afterbeing modulated by the DMD, the light reaches the lens 93 and isrefracted and reflected by a set of optical lenses including multipleconvex lenses, concave lenses, non-spherical lenses, etc. arrangedwithin the lens 93, and then are finally projected on the projectionscreen 94 to form projected images.

Some embodiments of the disclosure provides another projection displaydevice, as shown by the schematic diagram in FIG. 10, the projectiondisplay device comprises a laser light source 101. According to FIGS. 2,7 and 8, the laser light source 101 is a dual-color laser light sourceand comprises:

a blue laser emitter 11 configured to emit a blue laser light;

a red laser emitter array 12 configured to emit a red laser light;

a first diffusion element 31, which is fixedly disposed in opticalpath(s) of the blue laser light and the red laser light incidenting intoa light merging component 5;

the light merging component 5 configured to transmit the blue laserlight to a fluorescent wheel 4 and the red laser light to a seconddiffusion element 32;

the fluorescent wheel 4 configured to receive the blue laser light andemit a green fluorescent light which is transmitted to the seconddiffusion element 32 through the light merging component 5;

the second diffusion element 32, which is controlled to rotate andcomprises a non-diffusion zone configured to transmit the greenfluorescent light and a diffusion zone configured to transmit the bluelaser light and the red laser light output by the light mergingcomponent.

In some embodiments of the disclosure, the first diffusion element 31comprises two diffusion plates, wherein, one of diffusion plates isfixedly disposed in the red laser light optical path located between thered laser emitter array 12 and the the light merging component 5, andthe other diffusion plate is fixedly disposed in the blue laser lightoptical path located between the blue laser emitter array 11 and the thelight merging component 5.

The diffusion zone of the second diffusion element comprises a bluelaser light diffusion zone configured to transmit the blue laser lightand a red laser light diffusion zone configured to transmit the redlaser light; the material of the blue laser light diffusion zone is ablue color filter plate provided with blue diffusion particles; thematerial of the red laser light diffusion zone is a red color filterplate provided with red diffusion particles; the non-diffusion zone is agreen color filter plate.

In some embodiments of the disclosure, part of the blue laser lightincidenting into the fluorescent wheel 4 being reflected back into thelight merging component 5 and then being transmitted to the seconddiffusion element 32 through the light merging component 5;

As shown in FIG. 10, the projection display device further comprises alight conduit 102 and an image-forming component 103. The light conduit102 is disposed in the light emitting direction of the second diffusionelement. The image-forming component 103 is configured to form aprojected image based on an image been inputted and the light emitted bythe light conduit.

The laser light source 101 provides three primary lights whichsequentially output three primary colors, and then the primary colorsenter the light conduit 102. Based on the light emitted by the lightconduit 102 and an image been inputted, a projected image can be formedby the image-forming component 103.

The image-forming component 103 may be a DMD (Digital MicromirrorDevice) element or a LCOS (Liquid Crystal on Silicon) element.

For the projection display devices provided by the disclosure, themoving diffusion part can further increase more random phases on thebasis of the spatial phases increased by the fixed diffusion part bymatching a fixedly arranged diffusion part with a moving diffusion partof the laser light source part to jointly realize the speckledissipating for laser light, so that the degree of decoherence for theoriginal laser beam will be higher, more independent speckle patternscan be formed on the projected image, however, the more the independentspeckle patterns are, the weaker the speckle effect will be by using theintegral action of human eyes, and accordingly the speckle effect of thelaser light can be effectively weakened.

In the projection display devices provided by the technical solution ofthe disclosure, the laser light source can realize the effective speckledissipating for the laser light by using two diffusion parts, it hasfewer optical devices, simple structure and low complexity of opticalarchitecture, it is favorable for the miniaturized design of the opticalsystem, and at the same time, it also provides conditions for theminiaturized design of projection devices.

Although the preferable embodiments of the the disclosure have beendescribed, but the skills in the art can make other changes andmodifications for these embodiments once they know the basic creativeideas. Therefore, the attached claims can be explained to comprise thepreferable embodiments and all the changes and modifications within therange of the disclosure.

Obviously, the skills in the art can make various changes andtransformations of the disclosure without getting away from the spiritand range of the disclosure. In this way, if these modifications andtransformations of the disclosure are within the range of the claims andtheir equivalent technologies of the disclosure, the disclosure is alsointended to contain these modifications and transformations.

What is claimed is:
 1. A dual-color projector, comprising a blue laseremitter configured to emit a blue light; a red laser emitter configuredto emit a red light; a disk comprising a surface coated with greenfluorescent powder excitable by the blue light to emit a greenfluorescence; a first diffuser disposed in at least one of a blue lightpath of the blue light or a red light path of the red light; and asecond diffuser disposed on a side of a lightpipe in a light pathbetween the first diffuser and the lightpipe, wherein the seconddiffuser is configured to rotate and output the blue light, the redlight, and the green fluorescent light, to the lightpipe in a sequentialsequence.
 2. The dual-color projector according to claim 1, wherein, thefirst diffuser comprises a first diffuser sheet arranged in the bluelight path of the blue light and a second diffuser sheet arranged in thered light path of the red light.
 3. The dual-color projector accordingto claim 2, wherein, the first diffuser sheet is disposed in the bluelight path between the blue laser emitter and a light-combining element,and the light-combining element is configured to output the blue lightto the disk; and wherein the second diffuser sheet is disposed in thered light path between the red laser emitter and the light-combiningelement, and the light-combining element is configured to output the redlight to the second diffuser.
 4. The dual-color projector according toclaim 1, wherein, the first diffuser comprises a blue light diffusersheet arranged in the blue light path of the blue light between the bluelaser emitter and a light-combining element, and the light-combiningelement is configured to output the blue light to the disk.
 5. Thedual-color projector according to claim 4, at least one convex lens andat least one concave lens are arranged in the blue light path of theblue light between the blue laser emitter and the blue light diffusersheet.
 6. The dual-color projector according to claim 1, wherein, thefirst diffuser comprise a red light diffuser sheet arranged in the redlight path of the red light between the red laser emitter and alight-combining element, the light-combining element is configured tooutput the red light to the second diffuser.
 7. The dual-color projectoraccording to claim 6, at least one convex lens and at least one concavelens are arranged in the red light path of the red light between the redlaser emitter and the red light diffuser sheet.
 8. The dual-colorprojector according to claim 1, further comprising a light-combiningelement configured to receive the red light emitted from the firstdiffuser and the green fluorescence emitted from the disk, and outputthe green fluorescence and the red light in the same direction.
 9. Thedual-color projector according to claim 8, the light-combining elementcomprises at least one of a dichroic filter, a dichroic prism, or across dichroic prism.
 10. The dual-color projector according to claim 1,wherein, the second diffuser comprises a filter zone transmissive forthe green fluorescence, and a diffusion zone configured to betransmissive for the blue light and the red light.
 11. The dual-colorprojector according to claim 10, wherein, a portion of the seconddiffuser in the filter zone is a green filter, and the green filter isconfigured to receive the green fluorescence to pass through.
 12. Thedual-color projector according to claim 10, wherein the diffusion zonecomprises a blue light diffusion zone transmissive for the blue lightand a red light diffusion zone transmissive for the red light.
 13. Adual-color projector, comprising: a blue laser emitter configured toemit a blue light and a red laser emitter configured to emit a redlight; a disk comprising a first zone and a second zone, wherein thefirst zone is coated with green fluorescent powder, and the second zoneis transmissive for the blue light; a first non-rotating diffuserdisposed in a blue light path of the blue light between the blue laseremitter and a light-combining element; a second non-rotating diffuserdisposed in a red light path of the red light between the red laseremitter and the light-combining element; the light-combining elementconfigured to: receive the blue light output by the first non-rotatingdiffuser receive the red light output by the second non-rotatingdiffuser; output the blue light to the disk; and output the red light toa rotating diffuser in a first direction, wherein a first part of theblue light is configured to excite the green fluorescent powder to emita green fluorescence, and a second part of the blue light is configuredto pass through the second zone; a first reflector system configured tochange direction of the second part of the blue light passed through thesecond zone and render the second part of the blue light passed throughthe second zone to incident on the light-combining element, thelight-combining element is further configured to receive the second partof the blue light output by the first reflector system and the greenfluorescent emitted from the disk, and output the second part of theblue light and the green fluorescent to the rotating diffuser in thefirst direction; the rotating diffuser disposed on a side of a lightpipein a light path between the first non-rotating diffuser and thelightpipe, wherein the rotating diffuser comprises a green filterconfigured to filter the green fluorescence output by thelight-combining element, a blue light diffusion zone configured todiffuse the second part of the blue light output by the light-combiningelement, and a red diffusion zone configured to diffuse the red lightoutput by the light-combining element; and the lightpipe configured toreceive the green fluorescence output by the rotating diffuser, thesecond part of the blue light output by the rotating diffuser, and thered light output by the rotating diffuser.
 14. The dual-color projectoraccording to claim 13, wherein the rotating diffuser outputs the greenfluorescent, the second part of the blue light, and the red light intime sequence to the lightpipe.
 15. The dual-color projector accordingto claim 13, wherein the green filter is a non-diffusion green filter.16. The dual-color projector according to claim 13, the light-combiningelement comprises at least one of a dichroic filter, a dichroic prism,or a cross dichroic prism.
 17. A dual-color projector, comprising afirst laser emitter configured to emit a first light; a second laseremitter configured to emit a second light; a disk comprising a surfacecoated with fluorescent powder excitable by the first light to emit afluorescence which is different from the first and second light; a firstdiffuser disposed in at least one of a first light path of the firstlight and a second light path of the second light; and a second diffuserdisposed on a side of a lightpipe in a light path between the firstdiffuser and the lightpipe, wherein the second diffuser is configured torotate and output the first light, the second light, and thefluorescence to the lightpipe in a sequential sequence.
 18. Thedual-color projector of claim 17, wherein, the first laser is a bluelaser and the first light is a blue light; the second laser is a redlaser and the second light is a red light; and the fluorescence is agreen fluorescence.